Method, apparatus, and system for driving LED's
US7579786B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 4, 2007 |
| Grant date | Aug 25, 2009 |
| Priority date | — |
| Expiry date | Dec 27, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for driving LED's is disclosed, comprising the steps of receiving a desired intensity value, wherein the desired intensity value represents the desired intensity for the LED's; generating a first switching control signal, wherein the first switching control signal is a pulse width modulated signal whose duty cycle is based on the desired intensity value; switching the LED's on and off based on the first switching control signal, wherein the switching takes place when the desired intensity value is less than a first desired intensity value threshold; generating a desired constant current value based on the desired intensity value, wherein the desired constant current value represents the value of the desired constant current to drive the LED's; determining an actual constant current value, wherein the actual constant current value represents the value of the actual constant current driving the LED's; comparing the actual constant current value with the desired constant current value; and adjusting the output of the primary drive of the LED's so that the actual constant current value is equal to the desired constant current value. A system for providing LED bac…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.